Pitch indicator for bowling ball bores



Aug. 2, 1955 H. WATSON 2,714,256

PITCH INDICATOR FOR BOWLING BALL BORES Filed Feb. 15, 1951 2Sheets-Sheet l Aug. 2, 1955 WATSQN 2,714,256

PITCH INDICATOR FOR BOWLING BALL BORES 2 Sheets-Sheet 2 Filed Feb. 15,1951 Wick-Balke-Collendei' Company, a @orp'omtion of DelawareApplication February 15, 1951, Serial No. 211,054 4 Claims. (c1. 33 174This invention relates to a device for measuring the pitch of a borehole, and more particularly to a device which will measure the pitch ofa bowling ball finger hole.

It is a general object of this invention to produce a simple andaccurate pitch indicator for measuring the angle of a bore.

It is a more specific object of this invention to produce a device formeasuring the pitch of a bowling ball finger hole in which a pointer arminserted in the hole has means for automatically centering the pointerarm in the hole.

A further object of this invention is to produce a pitch indicator for abowling ball finger hole in which a threefo'rked fiat member has inversearcuate surfaces around the perimeter of two of the forks adapted toengage the spherical surface of a bowling ball and center a pivotedpointer arm over a finger hole; one end of the pointer arm indicatinggraduations on a scale positioned at the outer end of the third fork andthe other end of the pointer arm having at least one spring biased wallcontacting member in which uniform spring tension is maintained on twooutwardly extending Wall contacting arms having freedom of movement toaccommodate different sizes of bores.

Other and further objects of this invention will be apparent from theaccompanying description and drawings, in which:

Fig. 1 is a view of a bowling ball having the device of this inventionin position for measuring the pitch of a finger hole;

Fig. 2 is an enlarged broken section of the indicator and finger holeportion of Fig. 1;

Fig. 3 is a side elevation, partly in section, of the appa ratus shownin Fig. 2;

Fig. 4 is an enlarged view similar to Fig. 2 of the pointer arm and itscentering means;

Fig. 5 is a sectional view taken along the lines 5-5 of Fig. 4;

Fig. 6 is a sectional view taken along the lines 6 6 of Fig. 4;

Fig. 7 is a sectional view taken along the lines 77 of Fig. 4;

Fig. 8 is an exploded perspective view of the pointer arm and itsbacking piece; 7

Fig. 9 is a perspective view of one of the wall contact arms whichcenter the pointer arm in a bore; and,

Fig. 10 is a perspective view of one of the rivets which spaces thepointer arm from its backing member and also serves to anchor thebiasing springs for the wall contacting arms.

While my invention is susceptible of embodiment in many different forms,I have shown in the drawings and will herein describe one specificembodiment, with the understanding that the present disclosure is to beconsidered as an exemplification of the principles of the invention andis not intended to limit the invention to the embodiment illustrated.The scope of the invention will be pointed out in the appended claims.

States Patent 0 2,714,256 Patented Aug. 2, 1955 Bowling balls areproduced in a variety of weights and finger hole positions and it isdesirable that each bowler be equipped with a ball not only of a Weightmost' suited to him but also having finger grip holes most suited to hisgrip from the standpoint of spacing and pitch. Devices have been madewhich can determine the preferred spacing and pitch of the finger gripholes. Such devices usually have a surface which is spherical like abowling ball and may include a fingerhole which may be adjusted to avariety of positions with respect to the surface of the ball and thefinger hole itself may be set to a variety of pitches. Such a device isdisclosed in my copending application Ser. No. 180,112, filed August18,- 1950;

When the most suitable spacing and pitch of the grip holes for anyparticular bowler has once been indicated on a test ball, it isnecessary to determine this spacing and pitch in order that a ball blankmay be bored to repro duce the spacing and pitch of the grip holes ofthe test device. This invention comprises an apparatus which willmeasure the pitch. 7

Referring to Figs. 1 and 2, a gage body consisting of a three-forkedflat member indicated generally at 10 has two 'of its forks 11 and 12equipped with inverse arcua'te surfaces 15 and 14 adapted to engage thespherical surface of a bowling ball 15. There is a gap indicated at 16between the surfaces of the forks 11 and 12 and this gap issymmetrically spaced with respect to a third fork 17. The center of thegap 16 is on a radial line from the center of the bowling ball 15 andthe center of the fork 17, the two forks 11 and 12 having symmetricalconfigurations with respect to this center line.

On a spherical surface, the center of the fork 17 will always be along aradial line of the sphere. If the device is applied to a flat surfacethe center of the fork 17 will always be perpendicular to the flatsurface.

An indicator scale 18 is imprinted near the outer tip of the fork 17.The scale 18 cooperates with a .pitch indicator or pointer arm '19 toindicate the pitch of a bore in a manner to be more fully describedhereinafter. The pointer arm 19 is pivoted at the base of the fork 17around a pivot pin 21 which is located along the center line of the fork17. The pointer arm 19 has a backing member 22 which is coextensive withthe bottom portion of the pointer arm 19. The gage body 10 is retainedbetween the pointer arm 19 and backing member 22. Spacing between thepointer arm 19 and backing member 22 is maintained by a plurality ofrivets 23 which also serve to position some additional parts of thepointer arm. In the space between the pointer arm 19 and the backingmember 22, two sets of wall contacting members are located. Each ofthese wall contacting members consists of a pair of elongated fingers 24adapted to contact the walls of a bore. Each elongated finger 24 has acircular aperture 25 (Fig. 9) and an elongated cam slot 26. Each finger24 has a pivot pin 28 extending through the aperture 25 and the camslots 27 in the pointer arm 19 and backing member 22. The elongatedfingers 24 extend out in opposite directions as shown in Figures 2, 4, 6and 7 and the fingers are slidably mounted with respect to the rivets 23extending through the cam slots 26 and the pivot pins 28 which havefreedom of a short vertical movement in the oath "slots 27. The biasingeifect of the spring 29 forces the elongated fingers 24 outwardly sothat they will contact the walls of bowling ball finger holes or similarbores. In any one set of wall contacting members the elongated fingers24 will be positioned the same distance outfardly with respect to thepointer arm 19 since if one of the fingers 24 is fixed in position thecompanion finger 24 will be forced into the comparable position on theother side of the pointer arm 19. Thus, when the two elongated fingers24 of any set of wall contacting members contact the walls of a bore,

the pointer arm 19 will be forced into a position in the center of thebore. The operation of the device in measuring the pitch of a boreindicated at 31 will now be described.

The pitch indicator is first lined up so that the gap 16 is directlyover the bore 31. The center of the gap 16 being over the center of thebore. Since the gap 16 is designed to be greater in width than any boreto be measured, the bore may be centered by ascertaining that thedistance from the edge of the gap 16 to the edge of the bore 31 is thesame on both sides. The bottom portion of the pointer arm 19 is thrustinto the bore 31. The elongated arms 24 contact the walls of the bore 31and are pressed inward against the bias of the springs 29. As soon asthe surfaces 13 and 14 contact the ball 15 and the gap 16 is centeredwith respect to the hole 31 the pointer arm 19 will point slightly offthe center position as shown in the various figures provided the boreaxis does not lie along a radial line of the ball 15. Since the pointerarm 19 is lined up with the axis of the bore and the fork 17 is lined upwith a radial line of the ball 15, the indicator 18 now shows thedifference in spacing between the bore 31 and ball 15, or in otherWords, the pitch of the bore 31. The graduated scale 18 may be expressedin terms of an angle or in terms of the scalar displacement of the baseof the bore 31 with respect to the center of the ball 15. Since astraight line is determined by two points, the center lines of the holeand indicator will coincide. This enables a similar bore to be made onanother bowling ball.

If the bore should have a side pitch the gage body is rotated 90 and thereadings again taken as before. These two positions of the gage willthen give a reading of the forward or reverse pitch of the bore as wellas the side pitch thereof.

The device illustrated may also be used to indicate the pitch of a holebored in a flat surface. However, where the particular embodimentillustrated is used for this purpose, an error is introduced due to thefact that the pivot 21 is displaced some distance from the surface ofthe work piece. In order to obtain absolute accuracy it is necessarythat the pivot 21 be in the surface plane of the work piece. Thus, evenin the case of the bowling ball 15 a slight error is present in theembodiment illustrated since the pivot 21 is displaced slightly from thesurface of the ball. However, this error is so slight as to make nodiiference. In the case of aflat work piece, the error can be reduced byproviding the forks 11 and 12 with fiat surfaces 13 and 14 extendingoutward at a 90 angle from the fork 17.

I claim:

1. A pitch indicator for a bowling ball finger hole comprising: athree-forked flat gage body, the first and second forks havingcooperating inverse arcuate surfaces adapted to make contact with thespherical surface of a bowling ball, said arcuate surfaces having a gaptherebetween, said surfaces and gap being symmetrically spaced withrespect to the third fork, the third fork being adapted to extendoutwardly with its center along a radial line of said ball; an indicatorscale near the tip of said third fork, said scale having a zero readingalong a center line of the surface of said third fork; a pointer armpivoted at the center of the base of said third fork, said pointer armhaving a tip adapted to indicate a reading on said indicator scale and abottom end adapted for extension into a bowling ball finger hole; andtwo sets of wall contacting members at the bottom end of said pointerarm,

each set of wall contacting members consisting of a pair of elongatedfingers which are connected at one end to a pivot which has freevertical movement for a short distance along the center of said pointerarm and which are slidably connected to said pointer arm at pointsslightly displaced from said pivot, said pivot being vertically biasedby a spring whereby said elongated fingers are forced outwardly and actto center said pointer arm with respect to any surfaces encountered bysaid arms.

2. A pitch indicator for a bowling ball finger hole comprising: athree-forked fiat gage body, the first and second forks havingcooperating inverse arcuate surfaces adapted to make contact with thespherical surface of a bowling ball, and the third fork adapted toextend outwardly along a radial line of said ball; an indicator scalenear the tip of said third fork, said scale having a zero reading alonga center line of said third fork; a pointer arm pivoted at the center ofthe base of said third fork, said pointer arm having a tip adapted toindicate a reading on said indicator scale and a bottom end adapted forextension into a bowling ball finger hole, said bottom end having spacedvertical slots therein; and two sets of wall contacting memberspivotally attached along a center line of the bottom end of said pointerarm and springbiased outwardly from said pointer arm, the pivotalattachment between the wall contacting members of each set beingslidable in their respective vertical slots, said wall contactingmembers serving to line up said pointer arm along the axis of the fingerhole undergoing measurement.

3. A pitch indicator for a bore in a spherical surface comprising: agage body having at least two points for engaging a spherical surfacewhereby a center line of said gage body is lined up with a radial lineof said spherical surface; a pointer arm pivoted at the end of said gagebody nearest said two points, the pivot point for said pointer arm beingpositioned on said center line, said pointer arm having one end adaptedto extend into a bore and provided with cam slots and the other endadapted to cooperate with the gage body to indicate the pitch of thebore; and two pairs of wall contacting members pivotally attached tothe'end of said pointer arm which is adapted to extend into said boreand spring-biased outwardly from said pointer arm, each pair of wallcontacting members consisting of two elongated fingers pivoted togetherand having their pivotal connections slidable for a short distancevertically along their respective cam slots in said pointer arm, saidelongated fingers being disposed beyond the margin of said pointer armand extending upward in the direction of the pivot of said pointer armand away from said pointer arm whereby said elongated fingers contactthe sides of a bore and position said pointer arm with its center lineparallel with the axis of said bore.

4. Apparatus of the character claimed in claim 3 in which said pointerarm has a backing member and said wall contacting members pivot onspacer rivets connecting said backing member to said pointer arm.

References Cited in the file of this patent UNITED STATES PATENTS714,367 Demarty Nov. 25, 1902 1,411,911 Desbains Apr. 4, 1922 2,121,614Stark June 21, 1938 2,134,262 Phillips Oct. 25, 1938 2,546,532 Wade Mar.27, 1951

